U.S. patent application number 12/948288 was filed with the patent office on 2012-05-17 for angle adjustment apparatus for vehicle seat.
This patent application is currently assigned to TOYOTA BOSHOKU KABUSHIKI KAISHA. Invention is credited to Macit AKTAS.
Application Number | 20120119555 12/948288 |
Document ID | / |
Family ID | 46047114 |
Filed Date | 2012-05-17 |
United States Patent
Application |
20120119555 |
Kind Code |
A1 |
AKTAS; Macit |
May 17, 2012 |
ANGLE ADJUSTMENT APPARATUS FOR VEHICLE SEAT
Abstract
An angle adjustment apparatus for a vehicle seat
angle-adjustably connecting a first seat member and a second seat
member of the vehicle seat has a first member attached to the first
seat member, a second member attached to the second seat member and
rotatably mounted to the first member, a lock member axially
movably provided between the first member and the second member,
and a movement mechanism that axially moves the lock member
relative to the first member. The second member is provided with a
rotation regulation portion that allows the lock member to axially
move and regulates the lock member from circumferentially moving.
The first member has a plurality of internal teeth formed in an
annular-shaped internal peripheral surface. The lock member has an
external peripheral surface facing substantially externally in a
radial direction and facing the internal peripheral surface of the
first member, and a plurality of external teeth formed in the
external peripheral surface to be axially moved relative to and
engaged with the internal teeth of the first member.
Inventors: |
AKTAS; Macit; (Windsor,
CA) |
Assignee: |
TOYOTA BOSHOKU KABUSHIKI
KAISHA
Aichi-ken
JP
|
Family ID: |
46047114 |
Appl. No.: |
12/948288 |
Filed: |
November 17, 2010 |
Current U.S.
Class: |
297/366 |
Current CPC
Class: |
B60N 2/2218
20130101 |
Class at
Publication: |
297/366 |
International
Class: |
B60N 2/235 20060101
B60N002/235 |
Claims
1. An angle adjustment apparatus for a vehicle seat, the apparatus
angle-adjustably connecting a first seat member and a second seat
member of the vehicle seat, the apparatus comprising: a first
member attached to the first seat member; a second member attached
to the second seat member and rotatably mounted to the first
member; a lock member axially movably provided between the first
member and the second member; and a movement mechanism that axially
moves the lock member with respect to the first member, wherein the
second member has a rotation regulation portion that allows the
lock member to axially move and regulates the lock member from
circumferentially moving; the first member has a plurality of
internal teeth formed in an annular-shaped internal peripheral
surface; and the lock member has an external peripheral surface
facing substantially externally in a radial direction and facing
the internal peripheral surface of the first member, and a
plurality of external teeth formed in the external peripheral
surface to be axially moved relative to and engaged with the
internal teeth of the first member.
2. The angle adjustment apparatus for a vehicle seat according to
claim 1, wherein the external teeth of the lock member have a
tapered portion that is inclined with respect to an axis line and
faces the first member, and the angle size of the tapered portion
is 10.degree. or less with respect to the axis line.
3. The angle adjustment apparatus for a vehicle seat according to
claim 1, wherein the lock member comprises a plurality of lock
members that are provided circumferentially around the axial
center.
4. The angle adjustment apparatus for a vehicle seat according to
claim 1, wherein the first member has an annular portion that is
located closer to the axial center side than the internal teeth of
the first member, and a plurality of external teeth formed in an
external peripheral surface of the annular portion; and the lock
member has an internal peripheral surface facing the external
peripheral surface of the annular portion and facing substantially
toward the center of the radial direction, and a plurality of
internal teeth formed in the internal peripheral surface of the
lock member to be axially moved relative to and engaged with the
external teeth of the first member.
5. The angle adjustment apparatus for a vehicle seat according to
claim 4, wherein the internal teeth of the lock member have a
tapered portion that is inclined with respect to the axis line and
faces the first member, and the angle size of the tapered portion
is 10.degree. or less with respect to the axis line.
6. The angle adjustment apparatus for a vehicle seat according to
claim 1, wherein: the lock member has a plate-shaped lock main
body, and a projection that projects from the lock main body in a
plate thickness direction and extends in an arc shape; and the
external teeth are formed in an external peripheral surface of the
projection on the outer side of the arc radial direction.
7. The angle adjustment apparatus for a vehicle seat according to
claim 4, wherein: the lock member has a plate-shaped lock main
body, and a projection that projects from the lock main body in a
plate thickness direction and extends in an arc shape; and the
internal teeth are formed in an internal peripheral surface of the
projection on the center side of the arc radial direction.
8. The angle adjustment apparatus for a vehicle seat according to
claim 1, wherein each of the external teeth extends in a clamping
direction of a forming die for forming the lock member.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an angle adjustment
apparatus for a vehicle seat, the apparatus angle-adjustably
connecting a first seat member and a second seat member of the
vehicle seat.
[0003] 2. Description of Related Art
[0004] An angle adjustment apparatus is a recliner that
angle-adjustably connects a seat back to a seat cushion, for
example (see Related Art 1). A conventional recliner has an arm
plate provided to a seat back, a base plate provided to a seat
cushion, a slider axially movably provided between the arm plate
and the base plate, and a movement mechanism axially moving the
slider relative to the arm plate.
[0005] The arm plate has teeth on a surface facing the slider. The
slider is provided with teeth on a surface facing the arm plate,
the teeth being engaged with the teeth of the arm plate. The
movement mechanism has an axial member inserted into the slider,
and a lever connected to the axial member. A groove is formed in
the axial member, and a pin provided to the slider is inserted into
the groove. The groove axially moves the pin by axially rotating
the axial member with the lever. Thus, the slider axially moves
with respect to the axial member, and the teeth of the arm plate
and the teeth of the slider come close or are spaced apart from
each other. [0006] Related Art 1: U.S. Pat. No. 5,516,198
[0007] The teeth of the slider and the teeth of the arm plate,
however, extend radially. Therefore, the interval of the teeth is
large on the outer side of the radial direction, while it is small
on the center side of the radial direction. Since the interval of
the teeth is small on the center side of the radial direction, it
is not easy to accurately form the interval of the teeth. Thus, an
angle adjustment for a vehicle seat in which teeth can be formed
accurately has been required in a type having teeth that can be
engaged with each other in the axial direction.
SUMMARY OF THE INVENTION
[0008] In view of the above, the present invention provides an
angle adjustment apparatus for a vehicle seat. An aspect of the
present invention provides an angle adjustment apparatus for a
vehicle seat, angle-adjustably connecting a first seat member and a
second seat member of the vehicle seat, that includes a first
member attached to the first seat member; a second member attached
to the second seat member and rotatably mounted to the first
member; a lock member axially movably provided between the first
member and the second member; and a movement mechanism that axially
moves the lock member relative to the first member. The second
member is provided with a rotation regulation portion that allows
the lock member to axially move and regulates the lock member from
circumferentially moving. The first member has a plurality of
internal teeth formed in an annular-shaped internal peripheral
surface. The lock member has an external peripheral surface facing
substantially externally in the radial direction and facing the
internal peripheral surface of the first member, and a plurality of
external teeth formed in the external peripheral surface to be
axially moved relative to and engaged with the internal teeth of
the first member.
[0009] Accordingly, since the external teeth are formed in the
external peripheral surface of the lock member facing substantially
externally in the radial direction, each of the external teeth
extends axially. Thus, the interval of the external teeth is almost
unchanged over the entire length, and the interval of the teeth is
not narrow (small) on the center side of the radial direction,
differently from, for example, a case of teeth that extend
radially. Likewise, since the internal teeth of the first member
extend substantially axially, the interval of the internal teeth is
not greatly changed over the entire length. Accordingly, the
external teeth of the lock member and the internal teeth of the
first member can be formed accurately.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is further described in the detailed
description which follows, in reference to the noted plurality of
drawings by way of non-limiting examples of exemplary embodiments
of the present invention, in which like reference numerals
represent similar parts throughout the several views of the
drawings, and wherein:
[0011] FIG. 1 is a perspective view of a vehicle seat;
[0012] FIG. 2 is a perspective view of an angle adjustment
apparatus;
[0013] FIG. 3 is an exploded perspective view of the angle
adjustment apparatus;
[0014] FIG. 4 is an exploded perspective view of the angle
adjustment apparatus;
[0015] FIG. 5 is a cross-sectional fragmentary view of the angle
adjustment apparatus in a locked state taken along line V-V of FIG.
2;
[0016] FIG. 6 is a perspective view of a second member and a lock
member;
[0017] FIG. 7 is a perspective view of a part of a first member and
the lock member;
[0018] FIG. 8 is a partial perspective view of the lock member;
[0019] FIG. 9 is a cross-sectional fragmentary view taken along
line IX-IX of FIG. 7;
[0020] FIG. 10 is a cross-sectional fragmentary view taken along
line X-X of FIG. 7;
[0021] FIG. 11 illustrates a schematic configuration of a forming
die and the lock member showing a forming process of the lock
member; and
[0022] FIG. 12 illustrates a schematic configuration of a forming
die and a comparative lock member showing a forming process of a
comparative lock member.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] The particulars shown herein are by way of example and for
purposes of illustrative discussion of the embodiments of the
present invention only and are presented in the cause of providing
what is believed to be the most useful and readily understood
description of the principles and conceptual aspects of the present
invention. In this regard, no attempt is made to show structural
details of the present invention in more detail than is necessary
for the fundamental understanding of the present invention, the
description is taken with the drawings making apparent to those
skilled in the art how the forms of the present invention may be
embodied in practice.
[0024] An embodiment of the present invention is explained with
reference to FIGS. 1 to 12. As shown in FIG. 1, a vehicle seat 10
is a seat mounted to a vehicle and the like. The vehicle seat 10
has a seat back 11, a seat cushion 12, and a pair of angle
adjustment apparatuses (recliners) 1. The angle adjustment
apparatuses 1 angle-adjustably connect the seat back 11 and the
seat cushion 12. The seat back 11 has a first seat member (back
frame) 11a extending along a side surface of the seat back 11. The
seat cushion 12 has a second seat member (cushion frame) 12a
extending along a side surface of the seat cushion 12.
[0025] As shown in FIGS. 3 and 4, the angle adjustment apparatus 1
has a first member (ratchet) 2, a second member (guide member) 3,
and a lock member (pole) 4. The first member 2 and the second
member 3 have a circular plate shape. The first member 2 is
integrally provided with a ring-shaped flange 2a, a ring-shaped
ring main body 2b, and a plate-shaped plate main body 2c. The
flange 2a is positioned along an external periphery of the first
member 2; the ring main body 2b is positioned on the internal
periphery side of the flange 2a; and the plate main body 2c is
positioned on the internal periphery side of the ring main body 2b.
The flange 2a is rotatably retained by the second member 3 as shown
in FIG. 5.
[0026] As shown in FIGS. 3 and 4, the ring main body 2b is provided
to the flange 2a in an end portion of the axial direction on the
center side of the radial direction. The ring main body 2b has an
annular shape, and has an internal peripheral surface on the center
side of the radial direction. The internal peripheral surface has
an annular shape, and substantially faces the center of the axial
direction. A plurality of internal teeth 2b1 are formed in the
internal peripheral surface at the same interval. Each of the
internal teeth 2b1 extends axially.
[0027] As shown in FIGS. 3 and 4, the plate main body 2c is
provided to the ring main body 2b in an end portion of the axial
direction on the center side of the radial direction. An annular
portion 2d is formed in a surface of the plate main body 2c facing
the second member 3. The annular portion 2d projects toward the
second member 3 and extends annularly. The external peripheral
surface on the outer side of the radial direction of the annular
portion 2d faces substantially externally in the axial direction. A
plurality of external teeth 2d1 are formed in the external
peripheral surface at the same interval. Each of the external teeth
2d1 extends axially.
[0028] As shown in FIGS. 3 and 4, a plurality of projection pins 2g
projecting toward a controlling plate 7 are formed in a surface of
the plate main body 2c facing the second member 3. The projection
pins 2g can be inserted into elongated holes 7e formed in the
controlling plate 7 or contact the controlling plate 7, depending
on the relative angle between the controlling plate 7 and the first
member 2. When the projection pins 2g can be inserted into the
elongated holes 7e, the controlling plate 7 and the lock member 4
move toward the first member 2 so as to allow the lock member 4 to
be engaged with the first member 2. On the other hand, when the
projection pins 2g contact the controlling plate 7 without being
inserted into the elongated holes 7e, the lock member 4 is
regulated from moving toward the first member 2 by the controlling
plate 7 so as not to allow the lock member 4 to be engaged with the
first member 2.
[0029] As shown in FIGS. 3 and 4, a plurality of attachment
portions 2e are provided in a surface of the plate main body 2c
that is opposite to the second member 3. The attachment portions 2e
project in a direction away from the second member 3, and are
attached to the first seat member 11a shown in FIG. 1 by welding
and the like. A hole 2f is provided at the center of the plate main
body 2c, the hole 2f penetrating the plate main body 2c in a
thickness direction.
[0030] The second member 3 is integrally provided with a main body
3a and a flange 3f as shown in FIGS. 4 and 5. The main body 3a has
a circular plate shape, and the flange 3f is provided along an
external periphery of the main body 3a. A plurality of projections
3d are provided in a surface of the main body 3a that is opposite
to the first member 2. The projections 3d project in a direction
away from the first member 2, and are attached to the second seat
member 12a shown in FIG. 1 by welding and the like. A hole 3e is
provided at the center of the main body 3a, the hole 3e penetrating
the main body 3a in a thickness direction.
[0031] The flange 3f extends from an end portion of the axial
direction of the main body 3a to the outer side of the radial
direction as shown in FIGS. 4 and 5. The flange 3f has a ring
shape, and the first member 2 is slidably and rotatably provided to
an internal periphery of the flange 3f. A plurality of rotation
regulation portions 3b and recesses 3c are alternately provided
along the internal periphery of the flange 3f. The rotation
regulation portions 3b project from the flange 3f toward the center
of the radial direction. The recess 3c is provided between the
rotation regulation portions 3b, and the lock member 4 is provided
in the recess 3c.
[0032] The lock member 4 is integrally provided with a lock main
body 4a that is substantially fan-shaped; and a projection 4b that
projects from the lock main body 4a toward the first member 2, as
shown in FIGS. 4 and 6. The lock main body 4a is provided in the
recess 3c of the second member 3, and both side edges 4e of the
lock main body 4a are adjacent to the rotation regulation portions
3b. Thus, the lock member 4 is attached so as to be regulated from
circumferentially moving and be axially movable with respect to the
second member 3.
[0033] The projection 4b extends in an arc shape along an external
periphery of the lock main body 4a as shown in FIGS. 4 and 7. The
projection 4b has an external peripheral surface on the outer side
of the arc radial direction. The external peripheral surface faces
externally in the radial direction. A plurality of external teeth
4c are formed in the external peripheral surface at the same
interval. Each external tooth 4c extends axially. The projection 4b
has an internal peripheral surface on the center side of the arc
radial direction. The internal peripheral surface faces toward the
center of the radial direction. A plurality of internal teeth 4d
are formed in the internal peripheral surface at the same interval.
Each internal tooth 4d extends axially.
[0034] A biasing member 8 is provided between the lock member 4 and
the second member 3 as shown in FIGS. 4 and 5. The biasing member 8
is a flat spring that is provided with an annular base 8a and a
plurality of elastic sections 8b extending from the base 8a. A hole
8d is formed at the center of the base 8a. The elastic sections 8b
extend radially from the base 8a toward the lock member 4. The
elastic sections 8b contact the lock member 4 in a state where the
elastic sections 8b are elastically deformed, and thereby the lock
member 4 is biased against the first member 2.
[0035] As shown in FIGS. 4 and 5, the angle adjustment apparatus 1
has a movement mechanism 15 at the axial center thereof. The
movement mechanism 15 axially moves the lock member 4. The movement
mechanism 15 has an input member 5, a drive member (drive bush) 6,
and the controlling plate 7.
[0036] The input member 5 is integrally provided with a main body
5a, a projection 5c, and a flange 5b as shown in FIGS. 3 and 5. The
main body 5a has a column shape, and is provided with an engagement
portion 5d, 5e (male thread) in its external peripheral surface.
The projecting spiral 5d is projection-shaped, and the
groove-shaped spiral 5e is groove-shaped. The engagement portion
5d, 5e extend in a spiral shape so as to be screwed into other
engagement portion 6d, 6e (female thread) of the drive member
6.
[0037] The flange 5b extends radially externally from the main body
5a as shown in FIGS. 4 and 5, and the flange 5b is axially adjacent
to the second member 3. The main body 5a penetrates the second
member 3 and the first member 2. A washer 16 and an anti-drop
member 17 are attached to the tip end portion of the main body 5a.
The washer 16 is rotatably attached to the main body 5a and
contacts the first member 2. The anti-drop member 17 is fixed to
the main body 5a, and cooperates with the washer 16 to regulate the
input member 5 from being dropped out of the first member 2 in the
axial direction. Thus, the input member 5 is regulated from being
axially moving with respect to the first member 2 and the second
member 3 by the anti-drop member 17 and the flange 5b, while the
input member 5 is axially rotatable.
[0038] The projection 5c of the input member 5 axially extends from
the flange 5b, as shown in FIGS. 2 and 5. A lever 14, shown in FIG.
1, is connected to the projection 5c. The lever 14 extends forward
from the projection 5c such that the front end portion of the lever
14 is adjacent to a user seated on the vehicle seat 10. Lifting the
front end portion of the lever 14 rotates the input member 5 and
changes the angle adjustment apparatus 1 from a locked state to an
unlocked state.
[0039] The drive member 6 is integrally provided with a main body
6a, an end portion 6c, and a flange 6b, as shown in FIGS. 4 and 5.
The main body 6a has a tubular shape, and is provided with an
engagement portion 6d, 6e (female thread) in an internal peripheral
surface of the main body 6a. The groove-shaped spiral 6d is
groove-shaped, and the projecting spiral 6e is projection-shaped.
The engagement portion 6d, 6e extend in a spiral shape so as to be
screwed into the engagement portion 5d, 5e of the input member
5.
[0040] The main body 6a is inserted into the controlling plate 7,
the biasing member 8, and the second member 3, as shown in FIGS. 4
and 5. The external peripheral surface of the main body 6a has a
non-circular cross section, and has a rotation regulation surface
6a1. The rotation regulation surface 6a1 is provided so as to
oppose rotation regulation portions 7c, 8c, and 3g which are formed
on the periphery of the holes 7b, 8d, and 3e of the controlling
plate 7, the biasing member 8, and the second member 3,
respectively. With this, the drive member 6 is regulated from
axially rotating with respect to the controlling plate 7, the
biasing member 8, and the second member 3.
[0041] The flange 6b projects radially from the main body 6a so as
to be axially adjacent to the controlling plate 7, as shown in
FIGS. 4 and 5. The end portion 6c axially extends from the main
body 6a toward the first member 2. The end portion 6c has a
cylindrical shape, and is axially rotatably provided to the hole 2f
of the first member 2. When the lock member 4 moves axially from
the first member 2 toward the second member 3, the flange 6b pushes
the controlling plate 7, thereby causing the controlling plate 7 to
space the lock member 4 from the first member 2. With this, the
teeth of the lock member 4 (the external teeth 4c and the internal
teeth 4d) are spaced apart from the teeth of the first member (the
internal teeth 2b1 and the external teeth 2d1).
[0042] The controlling plate 7 has a disc-shaped main body 7a as
shown in FIGS. 3 and 4. The main body 7a is provided between the
first member 2 and each lock member 4. A claw 7d and a projection
7f are formed in a surface of the main body 7a facing the lock
member 4. The claw 7d passes a side of the lock member 4 from the
main body 7a, and latches onto a recess 4a1 formed in the opposite
surface of the lock member 4. The projection 7f projects from the
main body 7a toward the lock member 4 to be inserted into a recess
4f of the lock member 4. With this, the controlling plate 7 and the
lock member 4 are regulated from axially rotating with respect to
each other.
[0043] A retaining ring 9 is provided in an external periphery of
the angle adjustment apparatus 1 so as to prevent the first member
2 and the second member 3 from dropping in the axial direction, as
shown in FIG. 2. The retaining ring 9 is integrally provided with a
ring main body 9a, a first projecting portion 9b, and a second
projecting portion 9c. The ring main body 9a has a cylindrical
shape, and covers the external peripheral surface of the first
member 2 and the external peripheral surface of the second member
3.
[0044] The first projecting portion 9b has an annular shape as
shown in FIGS. 4 and 5, and projects from one end portion of the
axial direction of the ring main body 9a toward the center of the
radial direction. The first projecting portion 9b is axially
adjacent to the first member 2, and regulates the first member 2
from moving in a direction away from the second member 3. The
second projecting portion 9c has an annular shape, and projects
from the other end portion of the axial direction of the ring main
body 9a toward the center of the radial direction. The second
projecting portion 9c is axially adjacent to the second member 3,
and regulates the second member 3 from moving in a direction away
from the first member 2.
[0045] The angle adjustment apparatus 1 is normally in the locked
state as shown in FIG. 5. In the locked state, the biasing member 8
biases the lock member 4 against the first member 2. The external
teeth 4c of the lock member 4 are engaged with the internal teeth
2b1 of the first member 2, and the internal teeth 4d of the lock
member 4 are engaged with the external teeth 2d1 of the first
member 2. Since the lock member 4 is regulated from rotating with
respect to the second member 3, the first member 2 and the second
member 3 are regulated from rotating by the lock member 4. With
this, as shown in FIG. 1, the first seat member 11a and the second
seat member 12a are regulated from rotating by the angle adjustment
apparatus 1.
[0046] In order to unlock the angle adjustment apparatus 1 in the
locked state, the front end portion of the lever 14 is lifted
upward as shown in FIG. 1. The lever 14 then axially rotates the
input member 5, and the input member 5 is axially rotated with
respect to the drive member 6, as shown in FIG. 5. The engagement
portion 5d, 5e of the input member 5 axially pushes the engagement
portion 6d, 6e, thereby causing the drive member 6 to axially move
from the first member 2 toward the second member 3.
[0047] As shown in FIGS. 3 and 5, the flange 6b of the drive member
6 pushes the controlling plate 7, and the controlling plate 7
pushes the lock member 4 toward the second member 3 against the
biasing force of the biasing member 8. The external teeth 4c and
the internal teeth 4d of the lock member 4 are axially disengaged
from the internal teeth 2b1 and the external teeth 2d1 of the first
member 2. With this, the first member 2 becomes axially rotatable
with respect to the lock member 4, and the first member 2 becomes
axially rotatable with respect to the second member 3.
Consequently, the first seat member 11a can be angle-adjusted with
respect to the second seat member 12a as shown in FIG. 1.
[0048] When the force exerted on the lever 14 is released, the
biasing member 8 pushes the lock member 4 toward the first member
2, as shown in FIG. 5. The lock member 4 is engaged with the first
member 2, and the angle adjustment apparatus 1 is then returned
from the unlocked state to the locked state. When the seat back 11
is tilted forward more than a predetermined angle, however, the
projection pins 2g of the first member 2 are not inserted into the
elongated grooves 7e of the controlling plate 7 as shown in FIG. 3,
thereby contacting the controlling plate 7. The controlling plate 7
regulates the lock member 4 from being engaged with the first
member 2. Accordingly, the angle adjustment apparatus 1 is
maintained in the unlocked state, and the seat back 11 can be
angle-adjusted with respect to the seat cushion 12.
[0049] As shown in FIGS. 7 and 8, the lock member 4 is engaged with
the first member 2 in the locked state, so as to receive a force
from the first member 2. This force can be received after
distributed into shearing forces of first regions 4c1, 4d1 and
second regions 4c2, 4d2 of the lock member 4. The first regions
4c1, 4d1 are a boundary region between the teeth (the external
teeth 4c and the internal teeth 4d) and the lock main body 4a. The
second regions 4c2, 4d2 are a boundary region between the main body
of the projection 4b and the teeth (the external teeth 4c and the
internal teeth 4d).
[0050] As shown in FIG. 9, the first member 2 and the lock member 4
are provided with first tapered portions 2h, 4h and second tapered
portions 2i, 4i. The first tapered portion 2h is formed in the
internal teeth 2b1 of the first member 2, and inclines the internal
teeth 2b1 such that the tip end portion of the internal teeth 2b1
is farther away from the axial center than the base end portion
thereof. The first tapered portion 4h of the lock member 4 is
formed in the external teeth 4c, and inclines the external teeth 4c
such that the tip end portion of the external teeth 4c is closer to
the axial center than the base end portion thereof. The first
tapered portions 2h, 4h are set to be at 10.degree. or less such as
3-10.degree., for example 6.5.degree. with respect to the axis
line. Consequently, the internal teeth 2b1 and the external teeth
4c can surely be engaged with each other because they are guided by
the first tapered portions 2h, 4h when their positions displace in
the radial direction.
[0051] As shown in FIG. 9, the second tapered portion 2i is formed
in the external teeth 2d1 of the first member 2, and inclines the
external teeth 2d1 such that the tip end portion of the external
teeth 2d1 is closer to the axial center than the base end portion
thereof. The second tapered portion 4i of the lock member 4 is
formed in the internal teeth 4d, and inclines the internal teeth 4d
such that the tip end portion of the internal teeth 4d is farther
away from the axial center than the base end portion thereof. The
second tapered portions 2i, 4i are set to be at 10.degree. or less
such as 3-10.degree., for example 6.5.degree. with respect to the
axis line. Consequently, the external teeth 2d1 and the internal
teeth 4d can surely be engaged with each other because they are
guided by the second tapered portions 2i, 4i when their positions
displace in the radial direction.
[0052] Guiding tapered portions 2b2, 2d2 are provided in the first
member 2 as shown in FIG. 9. The guiding tapered portion 2b2 is
formed in the ring main body 2b so as to be adjacent to the outside
of the internal teeth 2b1 in the radial direction. The guiding
tapered portion 2b2 is inclined from a surface of the ring main
body 2b facing the lock member 4 toward the base portion of the
internal teeth 2b1. The guiding tapered portion 2d2 is formed in
the annular portion 2d so as to be adjacent to the center side of
the external teeth 2d1 in the radial direction. The guiding tapered
portion 2d2 is inclined from a surface of the annular portion 2d
facing the lock member 4 toward the base portion of the external
teeth 2d1. The guiding tapered portions 2b2, 2d2 are set to be at
10-20.degree., for example, 16.degree. with respect to a plane
perpendicular to the axis line. Consequently, the first member 2
and the lock member 4 can surely be engaged with each other because
they are guided by the guiding tapered portions 2b2, 2d2 when their
positions displace significantly in the radial direction.
[0053] A groove 4b1 and tapered surfaces 4b2, 4b3 are formed in a
surface of the projection 4b of the lock member 4 facing the first
member 2 as shown in FIG. 9. The groove 4b1 is formed in a central
area of the projection 4b in the radial direction, and extends
circumferentially. The tapered surface 4b2 is located between the
external teeth 4c and the groove 4b1, and is inclined from the end
portion of the external teeth 4c toward the bottom of the groove
4b1. The tapered surface 4b3 is located between the internal teeth
4d and the groove 4b1, and is inclined from the end portion of the
internal teeth 4d toward the bottom of the groove 4b1. The tapered
surfaces 4b2, 4b3 are set to be at 1-5.degree. (for example,
3.degree.) with respect to a plane perpendicular to the axis line.
Consequently, the end portion of the projection 4b hardly contacts
the first member 2, thereby allowing the first member 2 and the
lock member 4 to surely be engaged with each other in the axial
direction.
[0054] As shown in FIG. 10, the internal teeth 2b1 of the first
member 2 and the external teeth 4c of the lock member 4 axially
extend in a state of being tapered. The both surfaces of the
internal teeth 2b1 and the external teeth 4c have tapered angles
2j, 4j with respect to the axis line. By the tapered angles, the
internal teeth 2b1 and the external teeth 4c are engaged with each
other easily in the axial direction. Although it is omitted in the
drawings, the external teeth 2d1 of the first member 2 and the
internal teeth 4d of the lock member 4 also axially extend in a
state of being tapered. The both surfaces of the external teeth 2d1
and the internal teeth 4d have tapered angles with respect to the
axis line. By the tapered angles, the external teeth 2d1 and the
internal teeth 4d are engaged with each other easily in the axial
direction.
[0055] As shown in FIG. 11, the lock member 4 is formed by a
forming die 18. In order to form the lock member 4, a plate member
4x before forming is provided between an upper die 18a and a lower
die 18b of the forming die 18. When the plate member 4x is pressed
by closing the upper die 18a and the lower die 18b, the lock member
4 is formed by a cavity 18a1 of the upper die 18a and a cavity 18b1
of and the lower die 18b. The external teeth 4c and the internal
teeth 4d extend in the clamping direction of the upper die 18a and
the lower die 18b. Even if press is insufficient, therefore, the
top portion and the bottom portion of the external teeth 4c and the
internal teeth 4d can surely be formed.
[0056] In contrast, as shown in FIG. 12, a comparative lock member
20 is formed by a forming die 19. In order to form the comparative
lock member 20, a plate member 20x before forming is provided
between an upper die 19a and a lower die 19b of the forming die 19.
When the plate member 20x is pressed by closing the upper die 19a
and the lower die 19b, the lock member 20 is formed by a cavity
19a1 of the upper die 19a. A tooth 20a of the lock member 20
extends in a direction perpendicular to the clamping direction of
the upper die 19a and the lower die 19b. If press is insufficient,
therefore, there are cases where the top portion and the bottom
portion of the tooth 20 may not finely be formed.
[0057] As described above, the angle adjustment apparatus 1 has the
first member 2, the second member 3, the lock member 4, and the
movement mechanism 15 as shown in FIGS. 3 and 4. The first member 2
is attached to the first seat member 11a (see FIG. 1). The second
member 3 is attached to the second seat member 12a (see FIG. 1) and
rotatably mounted to the first member 2. The lock member 4 is
axially movably provided between the first member 2 and the second
member 3. The movement mechanism 15 is provided to axially move the
lock member 4 with respect to the first member 2. The second member
3 has the rotation regulation portions 3b that allows the lock
member 4 to axially move and regulates the lock member 4 from
circumferentially moving. The first member 2 has a plurality of
internal teeth 2b1 formed in an annular-shaped internal peripheral
surface. The lock member 4 has an external peripheral surface
facing substantially externally in the radial direction and facing
the internal peripheral surface of the first member 2, and a
plurality of external teeth 4c formed in the external peripheral
surface to be engaged with the internal teeth 2b1 of the first
member 2 by axially moving.
[0058] Accordingly, since the external teeth 4c are formed in the
external peripheral surface of the lock member 4 facing
substantially externally in the radial direction, each of the
external teeth 4c extends axially. Thus, the interval of the
external teeth 4c is almost unchanged over the entire length, and
the interval of the teeth is not narrow (small) on the center side
of the radial direction, differently from, for example, a case of
teeth that extend radially. Likewise, since the internal teeth 2b1
of the first member 2 extend substantially axially, the interval of
the internal teeth is not greatly changed over the entire length.
Accordingly, the external teeth 4c of the lock member 4 and the
internal teeth 2b1 of the first member 2 can be formed
accurately.
[0059] The external teeth 4c of the lock member 4 have the tapered
portion 4h inclined with respect to the axis line and facing the
first member 2 as shown in FIG. 9. The angle size of the tapered
portion 4h is 10.degree. or less with respect to the axis line.
Since the tapered portion 4h is small, the external teeth 4c face
substantially externally in the radial direction. Further, since
the tapered portion 4h is small, the external teeth 4c can be
engaged with the internal teeth 2b1 of the first member 2 gradually
deeply by axially moving the lock member 4 toward the first member
2. In this manner, the external teeth 4c can surely and easily be
engaged with the internal teeth 2b1.
[0060] As shown in FIGS. 3 and 4, a plurality of lock members 4 are
provided circumferentially around the axial center. Each lock
member 4 is engaged with the first member 2. Thus, the lock members
4 easily move circumferentially compared to a case where a single
large annular lock member extending around the axial center is
engaged with the first member. Each lock member 4 can, therefore,
easily be engaged with the first member 2 without being affected by
other lock members 4.
[0061] The first member 2 has the annular portion 2d that is
located closer to the axial center side than the internal teeth of
the first member 2; and a plurality of external teeth 2d1 formed in
the external peripheral surface of the annular portion 2d, as shown
in FIGS. 3 and 4. The lock member 4 has an internal peripheral
surface facing the external peripheral surface of the annular
portion 2d and facing substantially toward the center of the radial
direction; and a plurality of internal teeth 4d formed in the
internal peripheral surface of the lock member 4 to be engaged with
the external teeth 2d1 of the first member 2 by axially moving.
[0062] With this, the lock member 4 is engaged with the first
member 2 in the internal peripheral surface as well as the external
peripheral surface. The lock member 4 can, therefore, securely be
engaged with the first member 2. Further, since the internal teeth
4d of the lock member 4 are formed in the internal peripheral
surface of the lock member 4 facing substantially toward the center
of the radial direction, each of the internal teeth 4d extends
axially. Thus, the interval of the internal teeth 4d is almost
unchanged over the entire length, and the interval of the teeth is
not narrow (small) on the center side of the radial direction,
differently from, for example, a case of teeth that extend
radially. Likewise, since the external teeth 2d1 of the first
member 2 extend substantially axially, the interval of the internal
teeth is not greatly changed over the entire length. Accordingly,
the internal teeth 4d of the lock member 4 and the external teeth
2d1 of the first member 2 can be formed accurately.
[0063] The internal teeth 4d of the lock member 4 has the tapered
portion 4i inclined with respect to the axis line and facing the
first member 2 as shown in FIG. 9. The angle size of the tapered
portion 4i is 10.degree. or less with respect to the axis line.
Since the tapered portion 4i is small, the internal teeth 4d face
substantially toward the center of the radial direction. Further,
since the tapered portion 4i is small, the internal teeth 4d can be
engaged with the external teeth 2d1 of the first member 2 gradually
deeply by axially moving the lock member 4 toward the first member
2. In this manner, the internal teeth 4d can surely and easily be
engaged with the external teeth 2d1.
[0064] The lock member 4 has the plate-shaped lock main body 4a,
and the projection 4b that projects from the lock main body 4a in a
plate thickness direction and extends in an arc shape, as shown in
FIG. 4. The external teeth 4c are formed in the external peripheral
surface of the projection 4b on the outer side of the arc radial
direction. The projection 4b in which the external teeth 4c are
formed is reinforced by the lock main body 4a with respect to an
end portion thereof.
[0065] As shown in FIG. 4, the internal teeth 4d are formed in the
internal peripheral surface of the projection 4b on the center side
of the arc radial direction. The internal teeth 4d are formed in
the projection 4b in the same manner as the external teeth 4c, and
the projection 4b is reinforced by the lock main body 4a.
[0066] Each of the external teeth 4c extends in the clamping
direction of the forming die 18 for forming the lock member 4 as
shown in FIG. 11. Therefore, when the lock member 4 is press-formed
by the forming die 18, the top portion and the bottom portion of
the external teeth 4c can surely be formed even if a press force is
insufficient.
[0067] The present invention is not limited to the above-described
embodiments, but may be embodied in forms below. For instance, in
another embodiment, the first member 2 may be attached to the
cushion frame (first seat member) 12a, and the second member 3 may
be attached to the back frame (second seat member) 11a.
[0068] In another embodiment, the vehicle seat may have a seat back
as one of the first seat member and the second seat member, and may
have an arm rest or a table as the other of the first seat member
and the second seat member. In another embodiment, the vehicle seat
may have a seat cushion as one of the first seat member and the
second seat member, and may have a foot rest to support occupant's
calves as the other of the first seat member and the second seat
member.
[0069] In another embodiment, the first member 2 may not have the
external teeth 2d1, and the lock member 4 may not have the internal
teeth 4d. In another embodiment, the internal teeth 2b1 of the
first member 2 may not have the tapered angle 2j, and the external
teeth 4c of the lock member 4 may not have the tapered angle
4j.
[0070] In another embodiment, the angle adjustment apparatus 1 may
have one to three pieces of the lock members 4, or five or more
pieces of the lock members 4. In another embodiment, the angle
adjustment apparatus 1 may have a single annular lock member that
extends around the axis. In another embodiment, the lock member 4
may not have the projection 4b, and may have external teeth in the
external peripheral surface of the lock main body 4a.
[0071] The angle pitch of the external teeth 4c and the angle pitch
of the internal teeth 4d are set to be identical in the
above-described embodiments. However, the angle pitch of the
external teeth 4c may be different from the angle pitch of the
internal teeth 4d. For instance, the angle pitch of the internal
teeth 4d may be set to be greater than the angle pitch of the
external teeth 4c, thereby increasing the circumferential pitch of
the internal teeth 4d.
[0072] The vehicle seat 10 of FIG. 1 is mounted to a vehicle such
as an automobile, but may also be mounted to a boat, an airplane,
and the like.
[0073] It is noted that the foregoing examples have been provided
merely for the purpose of explanation and are in no way to be
construed as limiting of the present invention. While the present
invention has been described with reference to exemplary
embodiments, it is understood that the words which have been used
herein are words of description and illustration, rather than words
of limitation. Changes may be made, within the purview of the
appended claims, as presently stated and as amended, without
departing from the scope and spirit of the present invention in its
aspects. Although the present invention has been described herein
with reference to particular structures, materials and embodiments,
the present invention is not intended to be limited to the
particulars disclosed herein; rather, the present invention extends
to all functionally equivalent structures, methods and uses, such
as are within the scope of the appended claims.
[0074] The present invention is not limited to the above-described
embodiments, and various variations and modifications may be
possible without departing from the scope of the present
invention.
* * * * *